The approval in April of two changes to the International Construction Code (ICC) for 2018 should give builders greater flexibility in meeting the International Residential Code (IRC) and International Energy Conservation Code (IECC) in the areas of unvented attics and buried ducts, BUILDER reports.
According to Clarke Berdan, senior technical services leader for insulation manufacturer Owens Corning, the changes "allow the codes to catch up to building practices that have proven successful in the field and under the DOE's Building America program."
The 2006 IRC recognized the concept of moving the insulation off of the attic floor and onto the underside of the roof deck to create an unvented attic. f Moving the thermal barrier to the roof line permitted builders to place the HVAC equipment and ducts inside the conditioned (or indirectly conditioned) space. The heating and cooling loads were reduced and performance increased, providing alternatives to meeting the energy code.
For more on the change, see Berdan's article--the first in a planned two-part series.